Citing the billions more it will cost, Sen. Jim Webb asks VA secretary for explanation as he freezes funds to pay for expansion of coverage.

A U.S. senator who is also a highly decorated Vietnam veteran has called into question the spiraling costs of disability claims stemming from veterans' exposure to Agent Orange and other herbicides during the Vietnam War.

Late last week, Sen. Jim Webb, a Virginia Democrat and former secretary of the Navy, sent a letter to Veterans Affairs Secretary Eric Shinseki — another decorated Vietnam veteran — raising concerns over Shinseki's move to add three more illnesses to the list of ailments for which the VA provides compensation.

Webb asked the secretary to explain his decision to the Senate Veterans' Affairs Committee, on which Webb serves. At the same time, Webb also pushed through an amendment to an emergency supplemental bill that would delay by two months the transfer of $13.4 billion to cover the VA's costs for the new ailments while Congress reviews Shinseki's order.

At the core of Webb's concerns are the long-term costs of expanding the list to include ischemic heart disease, Parkinson's disease and a rare form of leukemia and whether the science is strong enough to justify the change.

"This single executive decision is estimated to cost a minimum of $42.2 billion over the next 10 years," Webb wrote. "A regulatory action of this magnitude requires proper congressional review and oversight."

In April the Tribune reported that the VA pays nearly $2 billion a year to Vietnam veterans suffering ailments associated with the herbicides, which were used during the war to defoliate jungles and destroy enemy crops.

The newspaper's analysis of the more than 3 million disability claims in the VA's compensation system estimated that Agent Orange-related illnesses — particularly Type 2 diabetes and prostate cancer — made up more than 10 percent of the $15.3 billion spent last year compensating Vietnam veterans for service-related injuries and illnesses.

Agent Orange-related ailments have contributed to an unprecedented surge in compensation costs during the past seven years, with disability payments for Vietnam veterans growing 79 percent since 2003, when the annual cost was $8.6 billion.

Shinseki's proposal would dramatically increase those amounts, according to a draft of the regulation published in the Federal Register in March. The VA's costs would be expected to surge by $13.6 billion in the first year, mainly because of retroactive payments to veterans who have been suffering from these ailments for years.

Ischemic heart disease is estimated to account for roughly 50 percent of the additional costs, which is what seems to have caught Webb's attention.

"Heart disease is a common phenomenon regardless of potential exposure to Agent Orange," he wrote in his June 4 letter to Shinseki.

Webb declined to comment for this report, saying his letter speaks for itself.

The senator also cited the example of Type 2 diabetes, another common illness on the list of ailments tied to herbicides. By the beginning of this year, the VA was compensating more than 265,000 veterans for Type 2 diabetes at a cost of about $732 million annually, according to Tribune estimates. The newspaper found that diabetes and prostate cancer account for more than 80 percent of all the costs associated with Agent Orange.

In additional to increased costs, the new illnesses promise to add thousands of claims to the VA's system, which is struggling to shrink a backlog of more than 500,000 claims.

Under the Agent Orange Act of 1991, the VA secretary may create regulations that presume certain ailments suffered by Vietnam veterans are the result of exposure to dioxin-tainted herbicides because of significant statistical connections.

The secretary's decisions are based in part on reviews of scientific studies conducted by the Institute of Medicine, an independent collective of scientists and doctors.

Shinseki's move to add more illnesses to the Agent Orange list won him accolades from many veterans groups, which had fought for decades to get the VA to recognize illnesses they say are connected to the herbicides.

Webb has been a staunch advocate for veterans throughout his career. Though his latest moves may invite attacks, Webb also raises legitimate questions, said Paul Sutton, former chairman of the Agent Orange committee for Vietnam Veterans of America.

"We're expecting the VA to do miraculous things when it has never been equipped to do miraculous things," he said.

Rick Weidman, executive director for policy and public affairs for the veterans group, said Webb — perhaps unwittingly — may trigger a larger debate about the long-term costs of war.

"If you can afford the bombs and bullets, then by God you can afford to care for those wounded by bombs and bullets and toxins," Weidman said.

World Focus correspondent Mark Litke and producer Ara Ayer travel to Vietnam to report on the long term impacts of Agent Orange/Dioxin on the Vietnamese land and people. This video report was part of their series on New Vietnam.